While I can't claim to be anywhere near an expert on this phenomenon, I have seen it widely remarked upon. The curse words of the English language, words used in denigrating, belittling and putting down others for a large part center on sex words. One hypothesis for the source of this concentration on sex is the purported puitanical nature of English-speaking cultures. Researchers indicate that in Catholic countries which are purportedly sexually licentious but which place greater taboo on sacriege, curse words are more centered around impious speech. So, for example in America, "Fuck you" indicates great insult in the speaker. From Spain comes one memorable example of a curse, "I piss on you and the five wounds of Christ." It is interesting to note that research indicates that the first impulses to use curse words originate in the limbic system, and not in the normal language centers of the brain. This seems to indicate that angry words may be an autnomic response. | 
